On the one hand this proposition is regarded as a syllogism: from thought Being is deduced. Kant more especially has objected to this that Being is not contained in thinking, that it is different from thinking. This is true, but they are still inseparable, or constitute an identity; their difference is not to the prejudice of their unity. Yet this maxim of pure abstract certainty, the universal totality in which everything implicitly exists, is not proved;[159] we must therefore not try to convert this proposition into a syllogism. Descartes himself says: “There is no syllogism present at all. For in order that there should be such, the major premise must have been ‘all that thinks exists’”—from which the subsumption would have followed in the minor premise, ‘now I am.’ By this the immediacy which rests in the proposition, would be removed. “But that major premise” is not set forth at all, being “really in the first instance derived from the original ‘I think, therefore, I am.’”[160] For arriving at a conclusion three links are required—in this case we ought to have a third through which thought and Being should have been mediated, and it is not to be found here. The ‘Therefore’ which binds the two sides together is not the ‘Therefore’ of a syllogism; the connection between Being and Thought is only immediately posited. This certainty is thus the _prius_; all other propositions come later. The thinking subject as the simple immediacy of being-at-home-with-me is the very same thing as what is called Being; and it is quite easy to perceive this identity. As universal, thought is contained in all that is particular, and thus is pure relation to itself, pure oneness with itself. We must not make the mistake of representing Being to ourselves as a concrete content, and hence it is the same immediate identity which thought likewise is. Immediacy is, however, a one-sided determination; thought does not contain it alone, but also the determination to mediate itself with itself, and thereby—by the mediation being at the same time the abrogation of the mediation—it is immediacy. In thought we thus have Being; Being is, however, a poor determination, it is the abstraction from the concrete of thought. This identity of Being and Thought, which constitutes the most interesting idea of modern times, has not been further worked out by Descartes; he has relied on consciousness alone, and for the time being placed it in the fore-front. For with Descartes the necessity to develop the differences from the ‘I think’ is not yet present; Fichte first applied himself to the deduction of all determinations from this culminating point of absolute certainty.